Although aspects of the present invention could be applied to indoor light fixtures, the following description will focus on the preferred application, outdoor light fixtures. There are many types of outdoor light fixtures, including lights which are mounted on posts and lights which are supported by brackets or short pointed ground stakes. The present invention is primarily directed toward post lights, although those ordinarily skilled in the art will recognize that aspects of the invention could be applied to other types of outdoor and indoor light fixtures.
Post lights should preferably have several features. Importantly, they should be affordable and weather resistant. Some post lights are made of wood and these have a tendency to rot when set into wet and soggy ground. Even the upper, above-ground portion of such post lights tends to rot due to exposure to weather elements. Post lights should also be easy to assemble and install since they are oftentimes installed by homeowners. Finally, the Applicants are of the opinion that post lights should be attractive as well: one of their primary functions is to enhance the attractiveness of homes and businesses, and if the fixtures themselves are unattractive or aesthetically incompatible with the grounds or architecture, they will be unacceptable to purchasers and will not fulfill their intended function. In view of the wide variety of tastes, styles, and uses, the Applicants believe that post lights should preferably be somewhat adjustable or flexible so that they can be modified to suit the purpose at hand.
Given the preferred features outlined above, it is perceived that plastic is an advantageous construction material. Although plastic post lights can be manufactured in a variety of ways, Applicants have found that it is preferable to fabricate such lights by extruding the post portion of the fixture and injection molding the bulb/lens assembly which sits atop the post. If the light fixture is so fabricated, however, joining the post and the bulb/lens assembly is problematical. Screws, rivets or other standard connectors are relatively expensive; sometimes require special or additional tools; and detract from a clean, high quality appearance. Further, they are often tamper-prone and can actually provide means for water to get inside of and damage the fixture. And, because the post is extruded it is impossible to use a threaded or bayonet connection between the post and the bulb/lens assembly. One aspect of the present invention is a technique for economically and securely joining an extruded post to an injection molded bulb/lens assembly. The technique disclosed herein provides such features in spite of the fact that the typical tolerance on an injection molded part is about 0.005 inch and the typical tolerance on an extruded three or four inch tube or post is on the order of 0.065 inch.
As discussed above, Applicants perceive that in addition to weather resistance and cost-effectiveness it is preferable to have a flexible or convertible post light that can be modified to suit the purpose at hand. Although louvers or baffles are normally found on "temple" lights such as the light shown in U.S. Pat. No. Des. 284,312, and not on post lights, the post light of the present invention preferably includes louvers which can be adjusted as desired. More louvers, spaced closer together, provide an oriental look with less outward-emanating light; fewer louvers spaced further apart provide a contemporary look and offer more outward-emanating light and greater light output in general.
The prior art, i.e., U.S. Pat. No. 1,396,936, issued to A. R. Locke, includes a lighting fixture which appears to have means for adjusting the spacing between its baffles or louvers. The Locke fixture includes a plurality of rings or louvers which are placed one above the other and are spaced apart by hollow spacing bushings located toward the outer edge of the fixture. The bushings are of such a height that there are slits between adjacent rings for the passage of light. By making the bushings of different heights the amount of light which escapes these slits can be varied. Relatively long screws which function as tie rods pass through the rings and bushings and tie the entire assembly together. Although the Locke fixture is advantageous in that it appears to include means for varying the distance between the rings or baffles, it is perceived that the adjustable bushing technique is disadvantageous for several reasons. For one thing, providing several different length bushings is expensive, and it is likely that the owner will misplace the bushings which are not currently being used. Also, assembly of the fixture is difficult. Finally, the bushings themselves are rather bulky and tend to unacceptably diminish the light emanating through the slits between the rings. The present invention addresses these problems: an aspect of the present invention is a technique for conveniently varying the number and distance between baffles or louvers such that the entire look and function of the light fixture can be varied depending on the application.